1. Field of the Invention
The present invention relates to a communication network, and particularly to a method for handoff from a Packet Switching domain to a Circuit Switching domain and equipment thereof.
2. Background of the Invention
In case of a Circuit Switching (CS) domain network and a Packet Switching (PS) domain network coexisting, when a Mobile Station (MS) supporting both CS domain communication and PS domain communication moves from the border of the PS network to the border of the CS network, handoff from the PS domain to the CS domain should be performed to maintain the continuity of the service.
In the prior art, there are two methods for handoff from the PS domain to the CS domain, one is to add an A16 interface to a Base Station Controller (BSC) in the current CS network and implement the handoff through the A16 interface.
According to the other method, a handoff entity control layer in the PS domain simulate the original service in the CS domain, specifically, a call in the PS domain is switched to a call in the simulated CS domain at first, and then the call is switched from the handoff entity control layer in the PS domain to the CS domain according to the existing call handoff method of the CS domain.